Which sentence contains an infinitive or infinitive phrase?

a. Starting tomorrow, I'm turning over a new leaf.

b. To me, that's the best story in the world.

c. Weren't you going to finish that song?

d. Save some of that cornbread for me.

C is the correct answer because it is the only sentence where there is an infinitive present, in this case that is 'to finish'. The other sentences do not contain an infinitive: 'starting' is a participle, 'am turning' is present continuous, 'is' is present simple, 'weren't going' is past continuous', and 'save' is imperative.